The Cerebrum. 



433 



per part of the pons, i.e., above its middle, there will be 

 paralysis of the face and limbs on the side opposite to the 

 lesion, whereas, one situated in the lower half of the 

 pons will press directly on the nucleus of origin of the 

 seventh nerve and cause paralysis of the face on the same 

 side as the lesion, but paralysis of the limbs on the opposite 

 side. The most characteristic symptom, then, of a tumor 

 of the pons, is paralysis of the limbs and tongue on the 

 opposite side, with paralysis of the sixth or seventh nerve 

 on the same side as the lesion alternate hemiplegia. A 

 'tumor of the superficial portion of the pons may cause 

 disturbance of sensation, since the sensory tract passes up 

 through the pons in the formatio reticularis. Should the 

 limbs be paralyzed on the opposite side, with the face and 

 tongue paralyzed on the same side as the lesion, then the 

 growth has passed down towards the lowest part of the 

 pons and has affected the nucleus of the hypo-glossal as 

 well as that of the facial. Sudden onset of alternate 

 hemiplegia is characteristic of pontine haemorrhage, 

 whereas, slow development of the symptoms indicate 

 a tumor. 



Lesions of the medulla may injure the glosso-pharyn- 

 geal, the pneumogastric, the spinal accessory or the hypo- 

 glossal nuclei, and, when so affected, there result such 

 symptoms as impairment or paralysis of deglutition, pho- 

 nation and articulation bulbar paralysis. A feature dis- 

 tinguishing true bulbar paralysis from pseudo-bulbar, the 

 result of the implication of the articulatory centres of the 

 cortex, is the fact that in the former there is associated 

 with the usual symptoms, paralysis of the palate as well. 



A tumor of the cerebellum, especially the middle lobe, 

 may cause difficulty of maintaining the equilibrium and 

 an unsteady reeling gait, while the early appearance of 

 pressure symptoms of the medulla shows that the tumor 



